After 6.8 million doses administered, CDC pauses vaccine to investigate 6 cases of rare blood clot

SAN LUIS OBISPO — County officials announce that they are following CDC and FDA recommendations to pause administration of the Johnson and Johnson vaccine as federal officials review six cases in which people developed a rare type of blood clot after getting the vaccine, one of which who has died according to national reports.

“Our goal is always to ensure that the vaccines are safe; we are focused on the health of our community and will continue to administer Pfizer and Moderna vaccines at our mass vaccination clinics to fight and prevent COVID-19 disease,” said Dr. Penny Borenstein, County Public Health Officer. “While adverse events like these blood clots appear to be extremely rare, we appreciate the agencies’ full focus on the health of our communities and will await further guidance from the CDC and the FDA before administering any further doses of the single-dose vaccine.”

As of this week, more than 6.8 million doses of the Johnson and Johnson vaccine have been administered in the U.S. After vaccination, six cases of a type of blood clot called cerebral venous sinus thrombosis (CVST) were seen in women between the ages of 18 and 48, approximately six to 13 days after vaccination.


While these adverse events appear to be extremely rare, the agencies are recommending a pause in the use of the vaccine out of an abundance of caution and until a thorough review is completed. This pause will also ensure that health care providers are aware of the potential for these adverse events and understand the appropriate treatment for patients if a blood clot occurs.
About 2,200 doses of the Johnson and Johnson vaccine have been administered at County’s mass vaccination clinics.

“If you received the Johnson and Johnson vaccine and develop a severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination, you should contact your health care provider,” Dr. Borenstein said. “We expect to receive more information following tomorrow’s meeting of the CDC’s Advisory Committee on Immunization Practices.”

For more information, visit or call the County’s Phone Assistance Center at (805)543-2444, available seven days a week, 8 a.m. to 5 p.m.